With the increase in different types of devices communicating over networks to servers and other computing devices, usage of third generation long term evolution (3GPP LTE) systems has increased. In particular, both typical user equipment (UE) such as cell phones and machine type devices (MTDs) currently use 3GPP LTE system. Machine Type Communications (MTC) from MTDs poses a particular challenge due to low energy consumption of the MTC UEs involved in such communication. In particular, MTC UEs are less computationally powerful and have less power for communication, and many are configured to remain essentially indefinitely in a single location. Examples of such MTC UEs include sensors (e.g., sensing environmental conditions) or microcontrollers in appliances or vending machines. In some circumstances, the MTC UEs may be located in areas where there is little to no coverage, such as inside buildings, or in isolated geographical areas. Unfortunately, in a number of cases, MTC UEs do not have sufficient power for communications with the nearest serving base station (enhanced Node B (eNB)) with which they communicate to satisfy normal Radio Link Control (RLC) protocol requirements within the current 3GPP standard. The RLC protocols may also cause similar problems for non-stationary wireless UEs, such as mobile phones, that are disposed in a network area with poor coverage, i.e., one in which the link budget is several dB below typical network values.
In particular, because transmission power cannot be increased either by the MTC UE or eNB, to achieve coverage extension and obtain additional dB in link budget, signals are repeatedly transmitted from the transmitting device (MTC UE or eNB) over an extended period to accumulate energy at the receiving device. While timing considerations in repeating the transmission in typical UEs such as smart phones is generally not an issue due to the communication rate of typical UEs, it may become problematic for MTC UEs that are to periodically provide information via the network. More specifically, because the communication rate between the MTC UE and eNB serving the MTC UE is relatively slow, and typical periodicity (which is set by the server rather than the MTC UE) is not low, communications may stall between the MTC UE and the serving eNB.
It would be therefore desirable for a network or UE to determine whether the use of an alternate RLC protocol for specific UEs in the coverage area is appropriate, as well as for UEs in a coverage enhancement mode to use the coverage enhancement RLC protocol.